Method and apparatus for cooling hot materials

ABSTRACT

A method and apparatus for cooling hot materials such as are produced in a burning operation in a kiln. The hot material flowing from the kiln is partially cooled by contact with a stream of gas as it is advanced along a first conveyor. The material is then separated into coarse and fine fractions by a stream of gas. The coarse fraction is crushed while the fine fraction is conveyed by a stream of gas to a cyclone separator, where the gas is partially cooled and where the fines are partially separated from the gas. The stream of gas from the cyclone separator is conducted to a bag-type dust collector where the fines are further separated from the gas stream.

HOT MATERIALS [75] Inventor: Harry E. Hoon, Jr., Strongsville,

Ohio

[73] Assignee: Envirotech Corporation, Menlo Park, Calif.

[22] Filed: Jan. 17, 1973 [21] Appl. No.: 324,551

[52] US. Cl 241/57; 241/81 [51] Int. Cl. B02c 21/00 [58] Field of Search241/17, 19, 23, 24, 57, 241/58, 81; 432/13, 20, 77

[56] References Cited UNITED STATES PATENTS 2,375,487 5/1945 Newhouse241/17 X 2,721,806 10/1955 Oberg et al.. 432/77 X 2,841,384 7/1958Peterson 241/19 2,904,323 9/1959 Cova et al 432/13 X 2 nd. Cooler UnitedStates Patent [191 [111 3,917,177 Hoon, Jr. [4 Nov. 4, 1975 METHOD ANDAPPARATUS FOR COOLING 3,089,653 5/1963 Ostberg 241/81 PrimaryExaminerGranville Y. Custer, Jr. Attorney, Agent, or FirmRobert E.Krebs; Thomas S. MacDonald [57] ABSTRACT A method and apparatus forcooling hot materials such as are produced in a burning operation in akiln. The hot material flowing from the kiln is partially cooled bycontact with a stream of gas as it is advanced along a first conveyor.The material is then separated into coarse and fine fractions by astream of gasfThe coarse fraction is crushed while the fine fraction isconveyed by a stream of gas to a cyclone separator, where the gas ispartially cooled and where the fines are partially separated from thegas. The stream of gas from the cyclone separator is conducted to abag-type dust collector where the fines are further separated from thegas stream.

2 Claims, 1 Drawing Figure US. Patent Nov. 4, 1975 METHOD AND APPARATUSFOR COOLING I'IOT MATERIALS BACKGROUND OF THE INVENTION It is known inthe art that the temperature of cement clinker discharged from a kiln isof the order of 2000 F., and that it must be cooled before it can besubjected to later operations. It is also known that such clinkercontains fines which should be recovered for subsequent use, and it isfurther known that the bag-type dust collector is the most efficienttype for separating particles from a gaseous stream. The hot clinker,however, heats the gas which is used for cooling it above a safetemperature which would quickly destroy the material used in the filterbags of the dust collector.

SUMMARY OF THE INVENTION The present invention includes a method andapparatus for cooling clinker and at the same time reducing thetemperature of the gaseous stream which is utilized in the process ofcooling, so as to maintain the temperature of the gaseous streamentering the bag-type dust collector below that which would damage ordestroy the material of which the filters are made. In the presentinvention a plurality of cooling steps are utilized with an intermediatestep of separating the hot material into coarse and fine fractions, andthen the coarse fraction is crushed. The fine fraction is introducedinto a moving stream of gas which flows into a cyclone separator, beforeit is conducted to a bag-type dust collector. Additionally, dust ladengas is taken off at various points in the system and conducted into thecommon stream which enters the cyclone separator. The stream of gas isthereby cooled as it moves toward the cyclone separator and is furthercooled within such separator. In the bag-type dust collector, the finesare further separated from the gas stream.

BRIEF DESCRIPTION OF THE DRAWINGS The drawing shows diagrammatically anarrangement of apparatus for carrying out the method of the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawing, designates akiln from the end 11 of which clinker is discharged onto a first cooler,indicated in general at 15. Such cooler is in the form of an upwardlyinclined conveyor onto which the hot material drops from the kilnthrough a hood 17 at the lower end of the kiln. The cooler has a housing20 extending the length thereof, which forms a tubular conduit throughwhich a cool gas may flow in contact with the material on the conveyor.The cool gas is introduced into the cooler 15 at 21 and the gas which isheated by contact with the hot material is discharged from the coolerthrough a conduit 25.

Heated gas flowing out of the kiln with the hot material rises in thehood 17 and is discharged therefrom by conduit 26. The hot materialleaving the cooler 15 drops by gravity through a conduit 30 across amoving current of cool gas and into a second cooler indicated in generalat 31. Such second cooler may have the same construction as the cooler15 but it is shown as being inclined downwardly, as opposed to theupward inclination of the cooler 15.

The moving current of cool gas across which the hot material flowsenters a housing 32 at 33 and picks up fine particles and therebyseparates the material into a coarse fraction and a fine fraction. Thecoarse fraction enters the cooler 31 while the fine fraction movesupwardly through the housing 32 and passes between a series of inclinedvanes 34, which direct the gas and fines into the housing 32 from whencethey flow into the discharge conduit 35.

As the hot material moves through the cooler 31 cool gas is introducedat 40 and, after being heated by the material, is discharged at theupper end of the cooler and into the housing 32, or into the conduit 25in accordance with the least resistance to the flow of the heated gas.

From the cooler 31 the material flows through conduit 41 to a crusherindicated in general at 45, from whence it moves through conduit 46 to astorage compartment 47. Dust which originates in the crusher is conveyedby conduit 50 to conduit 51, while dust which occurs in the storagecompartment is conveyed by conduit 52 into conduit 51 through conduit50. The streams of gas flowing through conduits 25, 26 and 35 arecombined in conduit 51 which in turn is connected to a cyclone separator55. The streams of gas are cooled as they flow through their respectiveconduits and the combined stream is further cooled in the cycloneseparator, where the fines are partially separated and are removed at 56and conveyed to a storage container 57.

The gas is discharged from the cyclone separator through conduit 58 andis introduced into the bag-type dust collector 60, from which theseparated fines are removed at 61 and conveyed through conduit 62 to thestorage container 57. As the gas stream leaves the cyclone separator itstemperature is below that which would be detrimental to the bag filters.A suction fan 65 maintains a constantly moving stream of gas through thesystem and discharges clean air to the atmosphere at 66.

The system of cooling hot materials in accordance with the presentmethod and apparatus can be carried out in an economical manner withoutthe need for specially designed expensive equipment. The systemeffectively cools the hot materials, efficiently separates the materialinto coarse and fine fractions and at the same time lowers thetemperature of the heated gas to the point where it is not destructiveof the material of which the bag filters are made.

I claim:

1. Apparatus for cooling hot material of different particle sizescomprising:

a. an upwardly-inclined conveyor for receiving the hot material in arelatively continuous stream and carrying the material upwardly;

b. a first housing surrounding said upwardly-inclined conveyor to form aconduit through which a gas stream passes from the lower end of saidupwardlyinclined conveyor to the upper end to contact and partially coolthe hot material on the conveyor;

0. means arranged at the upper end of said upwardlyinclined conveyor forseparating the partially cooled material into coarse and fine fractions;

d. a downwardly inclined conveyor for receiving the coarse fraction;

e. a second housing surrounding said downwardlyinclined conveyor to forma conduit through which a gas stream passes countercurrently to contactcool and separate the fine particle fraction from a and partially coolthe coarse fraction on the conthe gas stream; and veyor; j. means formaintaining a flowing gas stream through f. means for receiving andcrushing the coarse fracthe system.

tion from said downwardly-sloping conveyor; 5 2. An apparatus of claim 1in which the means for g. means for combining the gas streams exitingfrom separating the material into coarse and fine fractions the firstand second housing with the fine fraction; comprises,

h. a cyclone separator connected to receive said means for dropping thehot material by gravity across combined gas and fine fraction to cooland to para moving current of cool air as the hot material tiallyseparate the fine fraction from the gasstream; 0 passes from the firstcooling means to the second i. means for introducing the gas stream fromthe cycooling means.

clone separator into a bag-type separator to further

1. Apparatus for cooling hot material of different particle sizes comprising: a. an upwardly-inclined conveyor for receiving the hot material in a relatively continuous stream and carrying the material upwardly; b. a first housing surrounding said upwardly-inclined conveyor to form a conduit through which a gas stream passes from the lower end of said upwardly-inclined conveyor to the upper end to contact and partially cool the hot material on the conveyor; c. means arranged at the upper end of said upwardly-inclined conveyor for separating the partially cooled material into coarse and fine fractions; d. a downwardly inclined conveyor for receiving the coarse fraction; e. a second housing surrounding said downwardly-inclined conveyor to form a conduit through which a gas stream passes countercurrently to contact and partially cool the coarse fraction on the conveyor; f. means for receiving and crushing the coarse fraction from said downwardly-sloping conveyor; g. means for combining the gas streams exiting from the first and second housing with the fine fraction; h. a cyclone separator connected to receive said combined gas and fine fraction to cool and to partially separate the fine fraCtion from the gas stream; i. means for introducing the gas stream from the cyclone separator into a bag-type separator to further cool and separate the fine particle fraction from the gas stream; and j. means for maintaining a flowing gas stream through the system.
 2. An apparatus of claim 1 in which the means for separating the material into coarse and fine fractions comprises, means for dropping the hot material by gravity across a moving current of cool air as the hot material passes from the first cooling means to the second cooling means. 